Such a shading device is generally well-known. The known shading device is intended for a side window of a passenger vehicle. For shading the side window a flexible shading structure is provided and mounted on a winding shaft for winding up and off. The winding shaft is rotatably mounted on the vehicle below a vehicle lateral belt line behind a vehicle interior lining. The shading structure includes a dimensionally stable pull-out profile on a face end region that is in front in the pull-out direction, which profile is displaceable in vehicle-fixed lateral guiding rails between a rest position, concealed by the interior lining, and a shading position, moved up to an upper edge of the side window. The shading structure and the pull-out profile are led through a passage with the vehicle interior lining, which passage is closed by a cover in the lowered rest position. The cover is pivotable between an open position and a closed position, wherein pivoting of the cover is controlled by control means operable to open or close the cover as a function of the displaced position of the pull-out profile of the shading structure.
An object of the invention is to provide a shading device of the above mentioned type which allows secure and rattle-free transferring and securing of the cover in relation to the open and closed position thereof.
This object is achieved in that the control means comprise a control plunger engaging on the cover, which plunger is articulated to the cover in opposed pull and push directions, wherein the control plunger is in operative connection with the cover via a spring-elastic tensioning means which is spring-elastically tensioned in one movement direction and inactively relaxed in an opposite movement direction. According to the invention, the control plunger has a dual function in that, firstly, it operates to carry out force transmission to the cover in the manner of a plunger rod, in order to pivot said cover to its open position or its closed position. Secondly, the control plunger is associated with a spring-elastic tensioning means which exerts an additional elastic tensional force on the cover in a movement direction of the control plunger. Advantageously, the elastic tensional force is provided in the closing direction or towards the closed position of the cover, in order to tension said cover securely and rattle-free towards its closed position and, thus, to secure it in said closed position. An elastomer string or even a mechanical spring arrangement, like in particular a spiral tension spring or a spiral compression spring, can be provided as a spring-elastic tensioning means. Advantageously, the spring-elastic tensioning means comes into action during a tensile load of the control plunger. In a variant of the invention, the spring-elastic tensioning means can also be effective in case of a compressive load of the control plunger. Advantageously, merely one single control plunger with an associated spring-elastic tensioning means is provided to engage on the cover. A corresponding point of application can be provided in the region of a side flank of the cover or in the region of a cover center. In case the cover has a relatively great length, however, merely a small width, due to a relatively long but narrow passage in the belt line region of a corresponding interior lining, the cover is preferably reinforced along its longitudinal direction such that upon engagement of the control plunger in connection with the spring-elastic tensioning means in the region of a side flank of the cover, there is no significant torsion of the cover produced so that the tensional force acting on the cover, which is introduced in the region of a side flank, tensions the cover over its entire length towards the end position. The solution according to the invention is with particular advantage adapted to the use with side windows of passenger vehicles. Indeed, the solution according to the invention can also be used in the region of rear windows of passenger vehicles or on vehicle windows of other automotive vehicles operated on the road, in rough terrain or on rails. Therefore, the solution according to the invention is utile not only for passenger vehicles, but also for commercial vehicles and trucks as well as railway vehicles.
In an embodiment of the invention, the control plunger and the tensioning means are formed by a spiral tension spring which includes at least one terminal spring winding acting as a tensioning means in the pull direction, wherein all spring windings of the spiral tension spring are compressed to block in the push direction. This is an embodiment of the invention that is particularly simple and cost-efficient to produce. Once the spring windings of the spiral tension spring are compressed to block, the spiral tension spring acts as a plunger rod in the push direction. In the pull direction, preferably the large part of the spring windings are likewise spring-elastically blocked, in order not to impair the effect as a plunger rod in the pull direction. However, one or more terminal spring windings maintain their spring-elastically, in order to allow development of the desired spring-elastic tensioning effect in the pull direction. The wording that the spring windings are compressed to block does not necessarily mean that the spring windings contact on block. The wording merely means that the spring windings are blocked in their spring-elastic effect. In this functionality, the spiral tension spring acts rather as an at least essentially rigid plunger rod.
In a further embodiment of the invention, a spring wire of the spiral tension spring exhibits a spring rigidity great enough to exert a rigid plunger function on the cover in the push direction. This applies in particular to the free ends of the spiral tension spring which are articulated to the cover and a guiding element, respectively. The free ends need to have a rigidity such that under corresponding compressive or tensile loads, acting on the spiral tension spring, there is no bending or kinking occurring of the free ends that are not wound in spring windings.
In a further embodiment of the invention, the spiral tension spring is flanked on the exterior side and the interior side by a supporting body to clamp the spring windings in a force-fitting manner. The supporting body causes spring-elastic blocking of the spring windings and, furthermore, is configured such that in the pull direction one or more terminal spring windings are exposed in order to allow the desired supplementary elastic tensional force to be applied in the pull direction. The supporting body can be configured on the exterior side in the type of a sleeve encasing the spiral tension spring or on the interior side as a solid or hollow profile matched to the interior diameter of the spiral tension spring.
In a further embodiment of the invention, the supporting body is in the form of a cylindrical packing provided on the interior side. The packing has a dimensionally stable design and is preferably made of synthetic material in one piece.
In a further embodiment of the invention, the control plunger engages on one side of the cover, and an elastically tensionable pulling means engages on an opposite side of the cover, said pulling means acting on the cover only in the pull direction. The elastically tensionable pulling means can be an elastomer string or a spiral tension spring or a mechanical spring arrangement of similar design, and exert a tensional load on the cover in the closing direction. The elastically tensionable pulling means facilitates the closing function of the control plunger in the closing direction, in order to further reduce the risk of torsions acting on the cover. In the push direction of the control plunger, in order to transfer the cover into the open position, the elastically tensionable pulling means, held under permanent pre-tensioning, applies slight counteraction in order to allow clearance-free pivoting up of the cover, and in order to attenuate corresponding bearing tolerances of the cover.
In a further embodiment of the invention, the control plunger is articulated on a guiding element movable along a lateral guiding rail opposite to the point of application on the cover, which guiding element is in operative connection with the shading structure over a limited traveling distance.
In a further embodiment of the invention, the guiding element protrudes into a trajectory of a drive element of a dimensionally stable pull-out profile of the shading structure. Thus, a movement of the pull-out profile in the vicinity of its retracted rest position necessarily causes actuation of the guiding element, whereby by means of the control plunger—depending on the movement direction of the pull-out profile—a desired opening or closing of the cover is caused.
Further advantages and features of the invention will become apparent from the claims and from the description below of a preferred exemplary embodiment of the invention illustrated with reference to the drawings.